Double-walled container with base



Feb. 24, 1959 J. M. CANTY ETAL DOUBLE-WALLED CONTAIiNER WITH BASE FiledJan. 23, 1957 INVENTORS JOHN M. CANTY PETER-M. RIEDE /71;;

ATTORNEY United StatesPatcntO ,"Tcc

2,874,865 DOUBLE-WALLED CONTAINER BASE.

Application January 23, 1957, Serial No. 635,826

Claims. (Cl. 220- This invention relates to heat insulated double-walledcontainers having an inner vessel for holding a liquidload and an outervessel supporting said inner vessel and surrounding said inner vessel inoutwardly spaced relation so as to define therewith a jacket around theinner vessel which houses some type of vacuum insulation. Moreparticularly, this invention relates to a portable double-walledcontainer having an improved base for supporting the containervertically.

One of the principal objects of this invention is to provide a portabledouble-walled container having improved features in base constructionwhich make a light bodyconstruction for such containers practicable, anddurable enough to withstand impacts resulting from rough handlingencountered during usage.

Another object of this invention is to provide fora double-walledcontainer in which the inner vessel is supported by a single neck tube,a base member which will reduce or eliminate impact stresseson such necktube and thereby permit relatively thin-wall neck tube construction thatwill, in turn minimize heat leak into the inner container.

4 Another object of this invention is to provide an improved base memberfor supporting such containers vertically, which providesimproved safetyin the handling and operation of such containers.

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof the accompanying drawings which are intended to be exemplary only.

In the drawings:

Fig. l is a transverse vertical section, partly in elevation, of adouble-walled container embodying the present invention; and

Fig. 2 shows enlarged fragmentary vertical cross-sections through thetop and bottom supports for the inner vessel.

Referring now to the drawings, a double-walled container indicatedgenerally at 30 is made up of a pressuretight inner vessel 31 and apressure-tight casing 32 surrounding the inner vessel in outwardlyspaced relation to define therewith an intervening space 30a. The innervessel 31 is adapted to hold a body of liquid 31a and is supportedvertically within the casing 32 by a neck tube 36, which depends from ahead member 35 that is fixed to casing 32, as by welding 36a. The necktube 36 bears the entire vertical load of the inner vessel and mustcombine high strength and high impact qualities. For storing low-boilingliquefied gases, such as oxygen for example, Hastelloy alloy B, anickel-base corrosionresistant alloy, was found most suitable for itcombined high strength, high impact at low temperature and low thermalconductivity. In the storage of low boiling liquefied gases, the necktube 36 is preferably thin-walled along the major portion of its lengthto minimize heat leak. Enlarged end sections are provided, at 38, whichare respectively welded to the head and inner vessel where highestbending moments occur, so that the stress 2,874,865 Patented Feb. 24,-1959' in the welded joints connecting the neck to the head and to theinner vessel are low. To provide lateral support at the lower portion ofthe vessel while minimizing heat leak to the inner vessel, a centeringelement having low thermal conductivity and here shown as a glass-fiberreinforced plastic tube 39, is fixedly mounted on the inside wall of thecasing 32 along the longitudinal axis of the casing and is positioned toslidably and telescopically engage an annular element 40 centered on theinner bottom of the vessel 31. These co-operating elements center thevessel 31 within the casing 32 and provide lateral stability by takingside thrust loads on the container. At the same time they permitrelative vertical movement and thereby allow for thermal expansions andcontractions.

The space 3011 between the inner vessel 31 and the casing 32 houses aninsulation 33. This insulation is generally a vacuum-type insulation andthe space must be gas-tight.

The container is supported on a base assembly 41 which comprises aninwardly and upwardly extending, dished annulus 42, the inner rim 45 ofwhich serves as a seat on which the container casing bears downwardlyand to which the casing is welded, as at 44, and the outer rim of whichis fixed to a short downwardly extending flange 43 which rests on theground. The lower end of the flange is bent inwardly and reversely at 46for providing additional strength and for distributing load. The baseassembly has a spring-like action which enables it to absorb impactloads elastically. It is adapted to provide a predetermined amount ofresiliency so that the container casing when it issubjectedto a severepact while internalparts may receive damage and go unnoticed. Theelastic characteristics of the base are therefore limited to a shockload which is insufiicient to permanently deform the inner parts of thecontainer. This permits the container to be subjected to vertical impactloads causing elastic but not permanent deformation of the neck tube 36.Loads in excess of this limit will cause permanent deformation to thebase, and the attendant permanent absorption of considerable energyduring the deformation will avoid or minimize internal damage. In thisway damage will be generally confined to the base where repairs arerelatively easy, inexpensive and rapid as compared to repairs whichrequire entering the vacuum sealed casing. Furthermore, a deformed basewill serve as evidence that the container has received severe impact andwill. signal the need for close inspection to assure serviceability andsafety.

The above may be demonstrated by the following: a neck tube designed towithstand vertical accelerations up to about 20 gs (equivalent to aneight-inch vertical drop with a full container) and incorporated into acontainer provided with a base as described above will not be damaged invertical drops up to 48 inches because vertical drops in excess of eightinches will cause base deformations that will absorb sutficient energyto maintain loadings on the neck tube within the 20 g limit.

The base support and inner vessel supports are particularly adapted fora container requiring only a single fluid connection to the innervessel. In such case the neck tube 36 at the top of the container servesthe double function of providing a fluid connection to the inner vesseland the only vertical support for the inner vessel. This provides asystem in which minimum heat leak is achieved by the presence of asingle metallic conmotion to the inner vessel. It is to be understood,however, that the base and supporting feature of this invention are notlimited to such a system.

It should be apparent that various details of construction can be-;changed Without departing from the spirit and scope of the presentinvention .as defined in the following claims.

What is claimed is:

1. A container for storing low-boiling liquefied gas material, includinga casing, a vessel within said casing suspended vertically therefrom,said vessel being spaced inwardly from the casing to define therewith anintervening space, means in said space for restricting heat inflow tosaid vessel and for restricting lateral movement of the vessel relative.to the casing, a base member supporting the container vertically .andbeing elastically deformable only under impact loads insuflicient topermanently deform inner parts of the container.

2. A container for storing low-boiling liquefied gas material, includinga casing, ,a vessel within said casing suspended vertically therefrom,said vessel being spaced inwardly from the casing to define therewith.an intervening space, means in said space for restricting heat inflowto said vessel and for restricting lateral movement of the vesselrelative to the casing, a base member supporting the containervertically and comprising an annular plate having a central opening inwhich the bottom of said casing is received to be seated on said plate,and an annular flange depending downwardly from the outer margins ofsaid plate for supporting said plate on the ground, said base memberbeing elastically deformable only under impact loads insufiicient topermanently deform inner parts of the container.

3. A container for storing low-boiling liquefied gas material, includinga casing, .a vessel Within said casing suspended vertically therefrom,said vessel being spaced inwardly from the casing to define therewith.an intervening space, means in said space for restricting heat inflowto said vessel and for restricting lateral movement of the vesselrelative to the casing, a base member supporting the containervertically and comprising an upwardly and inwardly inclined annularplate having a uses V. r

a central opening into which the bottom of the casing is received to beseated on said plate, and an annular flange downwardly depending fromthe outer margin of said plate for supporting the plate vertically atits outer portions while leaving the plate free to move vertically atits inner portion, said base member being elastically deformable onlyunder impact loads insuflicient to permanently deform inner parts of thecontainer. 1

4. A container for storing low'boiling liquefied gas material includinga pressure-tight casing, a vessel supported vertically within saidcasing by a single tubular connection suspending the vessel from a topportion of the casing, said vessel being spaced inwardly from the casingto define therewith .an intervening space, means in said space forrestricting heat inflow to the vessel and for restricting lateralmovement of the vessel relative to the casing, and a base membersupporting the casing vertically and being elastically deformable onlyunder impact loads insufficient to permanentlydeforminner parts .of thecontainer. r.

-5. A container for storing low-boiling liquefied gas material includinga pressure-tight casing, a Vessel supported vertically within saidcasing by a single subular connection suspending the vessel from a topportion of the casing, said vessel being spaced inwardly from the casingto define therewith an intervening'space, means in said space forrestricting heat inflow to thevessel, .a

tubular centering element having low thermal conductivity andtelescopically mounted at opposite ends'in annular members attachedrespectively to the inner bottom portion of the casing and the outerbottom portion .of the inner vessel, said centering element restrictinglateral movement of the vessel relative to the casing, and .a basemember supporting the casing vertically and being elastically deformableonly under impact loads .insuflicient to permanently deform inner partsof the container.

l References Cited in the file .of this patent UNITED STATES PATENTS

